import sys
import math
from typing import List


# def xx(n: List):
#     result, root = float(n[0]), float(n[0])
#     for i in range(int(n[1]) - 1):
#         root = math.sqrt(root)
#         result += root
#     print(round(result, 2))


if __name__ == '__main__':
    while True:
        n = sys.stdin.readline().strip()
        n = n.split(' ')
        if len(n) > 0:
            result, root = int(n[0]), int(n[0])
            for i in range(int(n[1])-1):
                root = math.sqrt(root)
                result += root
            print(round(result, 2))
            # print(n_list)
        else:
            break


# if __name__ == '__main__':
#     while 1:
#         a = []
#         s = input()
#
#         if s != "":
#             for x in s.split():
#                 a.append(int(x))
#
#             print(sum(a))
#         else:
#             break

